The Star Gate. Space Cowboys, #1

If the men and women of Omega Force and Alpha Unit special ops teams thought what they faced in the Amazon jungle their last time out was rough.Well, they've been reassigned-to outer space-serving as Earth's advanced guard against encroaching threats. And this first threat is a big one. An artifact has been found on the moon, dating back over two billion years. Its origins and reasons for existence are unclear.
Whatever it is, it has picked now to come out of dormancy. The clock is ticking. Natty Young, the Nikola Tesla of his times-whose tech toys Omega Force and Alpha Unit use to keep them on the bleeding edge and one step ahead of the bad guys-has a theory about the artifact. And they're headed into space to find out if he's correct-aboard the Nautilus, a super-sentient starship so advanced to merely talk of its existence will cause you to go missing.
The Nautilus has discovered a star gate, which is also activating, and Natty doesn't believe it's a coincidence. But what they're up against-well, it has had a couple billion years head-start on the rest of us. To say Omega Force and Alpha Unit are going hunting for bigger game than they can take down may be the understatement of all time. OTHER OMEGA FORCE AND ALPHA UNIT NOVELS:MOVING EARTH (SPACE COWBOYS 2)MIND OF A CHILD: SENTIENT SERPENTSnote: all Omega Force and Alpha Unit novels are standalones, with complete story arcs.